i think the only type of tinting that looks good is black.. some cars have purple tinting, like the previous owner put on my car... ugly as shit. i hate it. mirror tinting is ugly, too.

anyways, mirror tinging can severly reduce the effectiveness of a radar detector, if you ever plan on using one. regular tinting can hinder a radar detector also, but not as much, and it should be fine if you don't go too dark.